A heel tap is a core exercise performed lying on your back, where you lower one leg at a time until your heel lightly touches the floor, then return it to the starting position. It’s one of the most common beginner-friendly moves used in physical therapy and fitness programs to strengthen the deep abdominal muscles without putting stress on the spine. The term “heel tap” can also refer to a neurological test used in clinical exams, though most people searching this phrase are looking for the exercise.
How the Exercise Works
Heel taps start with you lying flat on your back. In the most common version, your hips and knees are bent to 90 degrees, so your thighs point straight up and your shins are parallel to the floor. From this position, you slowly lower one foot toward the ground until your heel lightly taps the floor, then bring it back up. You alternate legs, typically for sets of 10 on each side.
A second variation keeps the legs straighter. You place your hands underneath your buttocks for lower back support, lift both legs into the air, then lower one leg with a straight knee until the heel touches down. This version demands more from your core because the longer lever of a straight leg increases the load on your abdominal muscles.
In both versions, the key is control. The lowering phase should be slow and deliberate, and your lower back should stay pressed into the floor throughout the movement. If your back starts arching off the ground, the exercise is too advanced for your current strength level, and you should stick with a smaller range of motion.
Muscles Targeted
Heel taps primarily work the transversus abdominis, the deepest layer of abdominal muscle that wraps around your midsection like a corset. This muscle acts as a natural stabilizer for the spine and pelvis. Unlike crunches or sit-ups, which target the visible “six-pack” muscles on the surface, heel taps train the stabilizing layer underneath.
The lower back muscles also benefit because they co-contract with the deep abdominals to keep your pelvis stable while your legs move. This makes heel taps especially useful for people dealing with lower back pain, since the exercise strengthens the muscles responsible for spinal support without requiring any spinal flexion or rotation. The pelvic floor muscles engage as well, working alongside the deep core to maintain trunk stability during the alternating leg movement.
Why Physical Therapists Use Them
Heel taps show up frequently in physical therapy programs because they teach your core to stabilize while your limbs move, which is exactly what your body needs to do during walking, running, and lifting. This concept, often called “anti-extension” training, builds the ability to resist your lower back from arching under load.
For people recovering from lower back injuries or postpartum weakness, heel taps offer a low-risk entry point. The movement is gentle enough that it rarely aggravates existing pain, yet challenging enough to produce real strength gains in the stabilizing muscles. Physical therapists often use the 90-90 position (hips and knees both at 90 degrees, ribs drawn down, light abdominal brace) as the starting variation, then progress patients to straighter legs or added resistance only once they can maintain control and keep their breathing smooth throughout the set.
Common Mistakes
The most frequent error is letting the lower back lift off the floor as the leg descends. This means the core has lost tension, and the hip flexors and spinal muscles are taking over. If this happens, reduce how far you lower your leg. Even a few inches of controlled movement is more effective than a full range of motion done sloppily.
Holding your breath is another common problem. Heel taps should be performed with steady, continuous breathing. Holding your breath creates excessive pressure in the abdomen and defeats the purpose of training the deep stabilizers to work during normal activity. Inhale as you lower the leg, exhale as you bring it back up.
Speed matters too. Rushing through repetitions turns the exercise into a momentum-driven movement rather than a controlled one. Each rep should take about three to four seconds total.
How to Progress Over Time
Once the basic 90-90 heel tap feels easy for 10 to 15 reps per side with no back arching, you can make the exercise harder in several ways. Straightening the working leg increases the lever arm and demands more from your core. You can also slow down the tempo, adding a pause at the bottom before returning. Holding a light weight between your hands overhead further challenges your ability to keep the ribs down and the back flat. Eventually, some people progress to lowering both legs simultaneously, though this requires significantly more core strength and should only be attempted once the single-leg version is completely controlled.
The Neurological “Heel Tap” Test
In a clinical setting, a heel-to-shin test is a completely different procedure that shares the casual name “heel tap.” During a neurological exam, a doctor asks you to place the heel of one foot on the opposite knee, then slide it smoothly down the length of your shin. The test evaluates coordination controlled by the cerebellum, the part of the brain responsible for smooth, accurate movement.
If someone struggles to keep their heel tracking along the shin, wobbling side to side or overshooting the target, it can signal a problem with cerebellar function. Conditions that may cause an abnormal result include cerebellar stroke, inflammation of the brain, and various metabolic disorders that affect the cerebellum. The test is the lower-body equivalent of the finger-to-nose test, where a doctor asks you to touch your nose and then their finger in alternation. Both tests assess the same brain region using different limbs.